Air or gas compressor.



B. RATHMBLL.

AIR 0R GAS COMPRESSOR.

APPLICATION FILED MAR. 26, 1908.

1. IBKEETS SHEET COLUMBIA PLANOGRAP" CO-.WANINOTDN. D. C.

Patented Aug. 22, 1911.

B. RATHMELL.

AIR on GAS COMPRESSOR.

APPLICATION FILED MAR. 28, 1908.

1,001,301. Patented Aug: 22, 1911.

4 BHEBTB-BHBET H. 7 W6. 6. 17 .5.

B. RATHMELL.

AIR OR GAS COMPRESSOR.

APPLIUATION FILED MAR. 2B, 1908.

H29 I 2'0, 2 I 2'/' WWM H Mum" Patented Aug. 22, 1911.

B. RATHMELL.

AIR 0R GAS COMPRESSOR. APPLICATION FILED MAR. 28, 1110s.

1 .001,301 Patented Aug. 22, 1911.

4 SHEETS-SHEET 4.

BERNARD BATHMELL, 0F LIVERPOOL, ENGLAND.

AIR 03 GAS COMPRESSOR.

Specification of Letters Patent.

Patented Aug. 22, 1911.

Application filed March 28, 1908. Serial No, 423,952.

a subject of the King of England, and a resident of 10 Victoria street, Liverpool, in the county of Lancaster, England, engineer, have invented certain new and useful linprovements in and Relating to Air or Gas Compressors, of which the following is a speciti cation.

My invention relates to compressors for air and other gases, more particularly of the vertical single acting type, such as are used for refrigerating and ice making purposes; of the kind in which the suction valve is provided with a cylindrical extension adapted to operate in guides contained with in, a piston: and also of the kind in which the discharge valve covers the full diameter of the cylinder bore.

My invention has for its main object to so construct both suction and delivery valves that the employment of pieces attached to the valves is obviated.

ll thus e'tl'ect simplification of manufacture of such compressors, reduction of liability to stoppage or breakdown during operation: and also render the machine capable o't being worked at high speeds.

In a compressor, according to my invention, the suction valve is in one piece, and is placed inside the piston. The valve head has a cylil'idrical extension which slides within radial wings or tins within the piston, which fins act as guides to keep the valve central with its seat. The valve is prevented from leaving its guides by a pin or pins placed in the piston and kept in position by the compressor cylinder walls; a gas passage is formed outside the cylindrical extension on the valve; the seating and radial guiding wings for the valve may be in one with the piston body, or alternatively disposed on a special seating fitted within the piston, such seating being locked in position by the same pin or pins which are used to retain the valve in its guides; the piston is hollow and holes are provided for the passage of gas to the suction valve. Further, according to this invention, the dclivery valve is made in one piece and ot the full diameter of the compressor bore, a seating being provided for it on the metal of the cylinder walls; said valve is provided with a cylindrical extension which slides in guides in the cylindrical head of the compressor, such head being of greater diameter than the compressor proper, the extreme part of the cylindrical extension on the valve enters a corresponding part of the compressors head or cover, and suitable slots are arranged to provide for cushioning when the valve lifts. A spring or springs may be placed within the cylindrical valve to bear against the compressor cover; gas passages are provided outside the cylindrical extension on the valve. I prefer to incloso the working part oi the compressor cylinder, and the compressor delivery or discharge head in a water jacket.

In single acting compressors, I provide an opening at the inner or suction end of the bore through which the suction or incoming air or gas is admitted to the suction side of the hollow piston; grooves, or other suitable means may be provided for opening the cmnpressor bore to the suction gas direct at the end of the stroke.

A machine made according to my invention may have one or more compressors worked from the same crank shaft; in a machine having more than one compressor a bearing is preferably provided between each crank. llurther, in a small compressor the connecting rod which operates it may be made with the small or cross head end of spherical shape, this spherical end bears against a metal shoe on the compression stroke, and is kept in position by a bell mouthed piece through which the connecting rod passes.

It may be here stated that 1: am well aware that ball joints are known and used in various apparatus, other than machines of the type herein described.

In a machine oil the incloscd type, according to this invention, the piston is of trunk pattern, and is made of two diameters, the larger diameter part is the piston proper, which is hollow; and the part ol smaller diameter extended For the connecting rod attaelnnent, and slides in a guide of corresponding diameter made solid with the compressor cylinder; inlet gas ports to the hollow piston are placed at the shoulder :lormcd by the change of diameters; this disposition of the gas ports in the shouldered part of the piston accelerates the speed oi? the gas passing into the piston on the suction stroke. Between the inlet gas ports at the piston shoulder and the point at which the connect-ing rod is attached, a solid partition is placed, so that the hollow piston is not open direct to the crank casing inside which the connecting rod works.

The crank casing or frame of an inclosed machine may be connected through a nonreturn or relief valve to the suction side of the machine. In such a machine the crank or cranks work through an oil bath, and the crank shaft passes through a bearing and gland; means are provided for ascertaining the oil level, and for filling in oil when required. The compressor cylinder is flanged and bolted to the frame of the machine. It is accurately centered by a bored guide on the frame into which an extension of the cylinder fits.

Drawings illustrating my invention are annexed hereto, in which Figure 1 is a sectional elevation of a com- .pressor, piston and valves, suitable for a machine of the open type (that is operated by connecting rod, cross head, and piston rod). Fig. 2 is a sectional plan through the compressor head taken as on line VV, Fig. 1. Fig. 3 is a vertical section through the compressor head taken as on line XX Fig. 2 but showing the discharge valve in elevation. Fig. 4 is a vertical cross section through the piston, but showing the suction or inlet valve in elevation. Fig. 5 is a sectional plan through the piston on line lV'lV Fig. 1. Fig. 6 is a section of a piston and valve ac cording to my invention, with the suction valve seating and guides disposed on a separate piece screwed into the piston body.

Fig. 7 is a sectional plan of Fig. 6 throu h center of retaining pin. Fig. 8 is a section of a. piston and valve, according to my invention, in which two or more short retaining pins are used instead of one long pin. Fig. 9 is a sectional plan of Fig. 8 through centers of retaining pins. Fig. 10 is a vertical section of a compressor, trunk piston, and valves, according to my invention, suitable for machine of inclosed type. Fig. 11 is a trunk piston adapted to be operated by a connecting rod with a spherical cross head end. Fig. 12 shows a relief valve fitted to the crank casing of an inclosed machine; and Fig. 13 shows a safety valve fitted inside the compressor discharge valve. Fig. 14 is a section through compressor head showing guiding fins disposed outside valve extension instead of inside compressor head; also shows a spring or discharge valve and a relief disk. Fig. 15 is a section through line Y-Y of Fig. 14:. Fig. 16 is a section through a piston showing the guiding fins disposed on outside of suction valve extension instead of inside piston body. Fig. 17 is a section through line ZZ of Fig. 15. In the several figures of the drawings like characters of reference denote like or corresponding parts wherever they occur.

Referring now more particularly to Figs. 1 to 5:l is the compressor cylinder body, 2 the compressor discharge head, 3 a flange for attaching compressor to the frame of the machine; and 4: is a spigot or guide formed outside the stuffing box to insure the compressor being truly central with frame; 5 is a flange for carrying the water jacket casing, and inlet and outlet water connections. 1, 2, 3, a, 5, are all in one piece and all concentric to the center line; this insures that all operative parts of the compressor are truly in line, and renders the machining of the compressor simple. 6 is the compressor cover, jointed and bolted to compressor head. The inlet or suction valve? has a cylindrical extension 8 as guide, at the bottom of which guide are lips or projections 9, which act as stops to limit the amount of valve lift; on the piston 10 is the valve seating 11, and also the guiding fins 12, 1.2 for the cylindrical guide 8 of the valve. Between the guiding fins 12, 12 and outside the guide 8 of the valve are the gas passages 13, 13. 1a is the retaining pin, which is made in length equal to the diameter of the piston, so that when the piston is in the cylinder this pin can not get out of place; pin 14 fits in the piston body at each end, and passes through holes 15 15 in the valve guide, which holes are made wider than the pin diameter to allow some rotary motion to the valve, and are of such depth that the top and bottom of same are clear of pin when the valve is seated, and also when the stops 9 of the valve are against the bottom end of the guiding fins 12, 12; the bottom ends of the fins 12, 12 are machined, so as to permit of the exact amount of valve lift required, and to provide a fair surface for the stops 9 to beat against; the pin 14: and width of the holes 15 are so arranged that, while some rotary motion is allowed, the valve cannot rotate far enough for the valve stops 9 to get clear from under the guiding fins 12, 12; if from any cause the valve stops 9 fail, the pin 1 1 constitutes a stop for limiting the valve lift, and prevents the valve from leaving the piston.

The suction valve disk or head 7, with the cylindrical guide 8 and projecting stops 9, 9 are all in one solid piece of metal, and no other pieces are screwed on or attached, thus any trouble from parts unscrewing or becoming loose is avoided; the valve seat may be made conical, flat or radial. The interior part of the guide 8 above the holes 15 is closed or left blank, so that some of the inlet gas flowing through the piston becomes trapped or baffled in this part and helps to lift the valve off its seat, and to keep it open throughout the suction stroke.

The disposition of the valve seating and the guiding fins integral therewith insures the one being in true alinement with the other, and when the seating is placed direct on the piston body, it is possible to lilttlit) the suction valve almost as large in diameter as the com n'essor cylinder bore; this gives large area, and ample gas passage through the valve, with small valve lift. Additional gas passagesn ay be provided by placing grooves 16, it in the cylil'ider, so that when the piston is at the bottom, the compressor space is open direct to the inlet gas space; this would insure compressor cylinder being absolutely tilled by gas at the full inlet pressure.

in ope 'ation the incoming or suction gas passes through inlet pipe 17 into the space 18, and through the ports 11$), 1%), in the lower part of the piston body, to the underside at the suction valve. The full bore of the compressor is covered by the discharge. valve 90 which has a seating 21. on the end of the CUUILHOSSOT cylinder. The valve Qt) has a cylindrical guide 22 extending upward, and made solid with the Vt lve; this guide slides between guiding tins in the compressor heal; between the fins 23, 23 are the vertizal gas passages Q- t, Q 111, while circumferential pat-sages 25 25 are provided by cuttii'ig away parts of the guiding tins 23, 23, above the passages 25, and the has 23 is a solid ring of metal 26, into which the end of the cylindrical guide 22 enters, and which provides a cut oil edge for the slots F3? in the guide :22. 'lhese slots are so arranged that when the valve lilits beyond a certain distance th slots 27 pass the bottom edge ot the ring 26 and thus inclose the sp-c which then forms a dash pot or gas cushion, and brings the 'alve to rest by increased pressure on top; this action tends to prevent any excessive li't't. A spring may also be placed on discharge valve it necessary somewhat as shown in Fig. 1 L when a s 'iiral spring St is adapted to bear against cover (3 on top of valve 20. By i'i'iaking the discharge valve oi? the full cylinder diameter, the piston may actually pass through the alve seating, it necessary, and the clearance at the end oi" the compr :ssion stroke is reduced to a minimum; am ple gas pass-sage is secured, and the valve liitt can be very small. it turther ad 'antage is that the large alv gives such a tree exit from the coi'iipressor that it, from any cause, liquefiedv gas gets into the cylimlcr. it can be discharged easily without danger of dan'iaging the compressor cover. The valve 20 and guide it) being solid with one another, there are no small parts to get loose or b oak, the valve seating and the guiding tins are on the same metal which insures accurate alinement; the seating may be tlat, conical or 'adial. The discharge gas passe. from the compreiaier head through the branch 2t) to the pipe 30; 31 is the compressor cover joints; 32 is the water jacket space, and envelops the compressor cylinder, the discharge head, and b'anch, and the compressor cover; 33 is the water jacket (it sing, which is attached to the llange lasing may be either open or closed at top.

Referring now to .i'iigs. t3 and Tz lt'hen, for any reason, it desired to put in a separate 'alve seating on the piston body, the piston, valve, and 'alve seating piece, may be ar 'anged as shown in these .tigures. 7 is the suction valve with cylindrical guide 8 and stops 9, t). 12, 12 are the guiding tins and .11 the valve so: ting, both being disposed on the separate seating piece 3t, which is screwed into the piston body it); the seating piece 3t is screwed hard down on the piston body 10, and the retaining pin Ll passed through the two o't them, and through the holes l5 in the valve guide; the pin it is a lit in the piston body, and in the seating piece and prevents the lat er 'lrom slacking l ack; the holes 15 in the guidi are larger than the diameter of the retaining pin-as beitorc described---; the passages 1; .13, for the gas are between the guiding tins 12, 12 in the seating piece, and outside the cylindrical guide 8 ot the valve.

Referring now to Figs. 8 and 9: ill) alternative arrangement is shown whereby the suction valve is lett free to rotate. ln this arrangement, the valve T has a eylindri cal guide 8, but instead of the stops t), it is provided with an annular recess 5--- into which project the ends ojl two or more re taining pins 36, 36; these pins lit in the piston body, and are kept in place by the ovlinder walls; and prevented from l lt'tljet'tlllf into the valve recess too much by shoulders on the pins. The recess IE5 is deeper than the diameter of the projecting ends of the pins, so that when the valve is on its seat, the top ot the recess is clear ot the top ot the pins. and the distance between the bottoms of the pins and the bottom ol the recess ,l ixes the amount oil valve lift. The pins ill) prevent the "alvc .l rom liaving its guides, and at the same time leave it tree to revolve. 1: ssages lit, .13, for the gas are provided, as be'lorc. This ar 'angcment may also be cmployed when a separate s *ating piece is screwed into the piston. Alternatively, in either suction valve the guiding tins may be placed on the exterior ot the cylindrical valve extension, instead ol. on the interior ot the piston, or the special .--:cating piece; in which case the interior oi the piston, or of the special seating piece. will be a plain bored guide to receive the valve guiding tins. Such a valve is shown in i igs. 1t; and 17 where the 'alve h *ad 7 has a cylindrical extension 8 on which are 'lormcd the ribs or tins 12 adapted to slide within the plain guide two opposite tins have projections 9, 9, at these lower ends which act as stops LOO by coming against the under side of the solid guide 60; to allow for the insertion of these projecting stops 9, 9, two slots 59, 59, are formed in the guide 60; after valve guide is lowered into position through these slots, it isslightly turned to bring stops under solid part and pin 14 put into position. Further, in the compressor head the guiding fins for "the valve may be placed on the exterior of the cylindrical extension of the valve, instead of 011 the compressor head, this latter being then bored plain, as shown in Figs. 14 and 15 where the valve has cylindrical extension ..2 on which are formed the guiding fins 23 which are cut away at top and bottom to give circumferential passage for gas. The slots 27 as before described engage with a cut off edge 57 formed on the compressor cover; gas passages 24, 24 are formed between the fins as before described. The outlet passage 58 may be led straight out.

Referring now to Figs. 10 and 11;l*ig. 10 shows a compressor cylinder and trunk piston for a machine of the inclosed type, that is, with the crank and connecting rod operating within an inclosed casing-gene1 ally in an oil bath. The inlet gas is taken to the compressor cylinder through the pipe 17 communicating with the suction space 18; the compressor cylinder has an extension 4 which acts internally as a guide for the piston trunk, and externally as a spigot in the corresponding sleeve 87 on the crank casing, to insure the compressor being central with same. The piston body 10 is made hollow for the suction valve, and is integral with a trunk 38 of smaller diameter, to which it is joined by a short taper piece 39; in the shoulder so formed are placed the inlet gas ports 19, 19. On the suction or down stroke the action of this descending shoulder is to force the gas from the annular space he neath it, and, between ports 19, 19, to the suction valve. The extended trunk is utilized for coupling up the connecting rod, and serves to prevent oil splashing into the compressor; small grooves are placed circumferentially on the exterior of the trunk to carry up some oil for the lubrication of trunk and cylinder; the interior of the piston trunk is closed at 40, so that there is no direct opening between crank casing and compressor cylinder bore.

Fig. 11 shows a method, suitable for small machines, of coupling up the connecting rod to the trunk piston. The connecting rod end 41 is made spherical in shape, and bears, during the com ression stroke, on a shoe 42 fitted inside the trunk; the spherical end is kept up in place by a nut 43, this nut being kept from slacking back bya pin through the trunk metal. F or a single acting compressor, this spherical end gives greater bearing surface on the compression stroke than can be obtained by the use of the ordinary gudgeon pin in a trunk piston. It should be noted that this spherical end can be similarly used in the cross head of small open type compressors.

In a machine of the inclosed type, '1 prefer to lit a relief valve to the crank casing, in order to prevent any accumulation of pressure, higher than the suction pressure, inside the crank casing. Fig. 12 shows a method of doing this z-lnto the closed partition above the connecting rod end, a plug 44 is screwed and fastened; this plug carries a relief valve 45 with suitable guiding wings, the relief valve is held in position by a light spring 46 hearing against an adjustable nut 47, which is prevented from moving when once set by a pin 48, the said pin be ing unable to shift after the plug 44 is screwed into position; holes are left in nut 47 for gas escape. When the spherical ended connecting rod is fitted this relief valve will be placed in the bearing shoe 42 shown in Fig. 11. The act-ion being that when any pressure accumulates in the crank casing materially higher than the suction pressure within the hollow piston, the valve 45 will be lifted and the pressure relieved.

Tn compressors, according to this invention, the possibility of accident, which arises if the machine is started with the discharge stop valve closed, is guarded against by placing asafety valve inside the compressor discharge valve, and this is shown in Fig. 13. In the solid discharge valve 20 a valve seat is machined, and a valve 49 placed therein; this valve is held to its seat by the spring 50 bearing against the nut 51, which is adjustable and can be set to give way under any suitable excess of pressure. Thus should the machine be started with the discharge conduit blocked, the pressure inside the cylinder head will rapidly rise until it reaches the limit at which the safety valve is set to open; when the valve opens this pressure relieves itself into the cylinder, and prevents the suction Valve from being opened, and no more gas will be pumped. Alternatively, instead of a spring loaded valve, a'

diaphragm of thin metal may be placed over a small relief hole, the metal being of such a thickness that it will burst under the excess pressure. Such an arrangement is shown in Fig. 14 where 52 is a thin metal disk of known strength held in place over a small hole 55 in discharge valve by a screw plug with a hole 56 bored through allowing gas pressure to come direct on disk: a boss 54 is formed on back of discharge valve and machined out for disk and screwed plug: the disk metal is soft enough to make a gas tight joint. This arrangement of placing the safety valve within the discharge, valve avoids the necessity of fitting the pipe connections required when a relief valve is fitted outside to blow oil the discharge branch into the suction branch, or, on the other hand, avoids the loss of gas which is sustained when a relief valve is placed so as to blow oii' into the atmosphere.

ltliaving now described my invention, what I claim as new and desire to secure by Letters llat-cnt is:-

1. in a compressor for compressing air or other gas; in con'ibination, a piston in one piece, a valve seatin valve guides, and *alve stops integral with said piston, a suction valve comprising a valve head, a hollow cylindrical extension adapted to work within said guides on the piston, and outward projections on the lower end of said cylindrical extension adapted to engage with said valve stops on the piston, said valve head, cyliir drical extension, and stops being integral with each other, a safety retaining pin tor said valve adapted to pass through said cylindrical extension on the 'valvi and through said piston and be maintained in position by the cylinder wall, and means whereby said valve is permitted certain rotary motion and normally prevented from knocking" against said pin.

2. In a eomi 'jressor tor compressing air or other gas; in combination, a piston in one piece, a valve seating, valve guides, and valve stops integral with said piston, a suc tion valve comprising a valve head, a hollow cylindrical extension adapted to work within said guides on ti o piston, and. outward proj cctions on the lower end of said cylindrical extension adapted to engage with said valve stops on the piston, said valve head, cylin drical extension, and stops, being integral with each other, a safety retaining pin for said valve adapted to pass through said eylindrical extension on the valve and through said piston and be maintained in position by the cylinder wall, means whereby said valve is permitted certain rotary motion and norn'ially prevented from knocking against said pin, a discharge valve seating, guides, and inwardly projecting ring all integral with each other and disposed within the discharge chamber of the compressor, and a discharge valve having integral therewith a hollow cylindrical extension adapted to work in the said guides within the discharge chamber, said discharge valve being of not less diameter than the compressor bore.

3. In a COIIIIPI'QSSOI' "for compressing air or other gas, a compressor cylinder and gas discharge chamber having integral therewith a discharge valve seating ot the tull cylinder dian'ieter, discharge valve guides and an inwardly projecting ring, a disclmrge valve of not less diameter than the diameter of the cylinder bore having integral therewith a hollow cylindrical extension adapted to work within the said guides, and ports in said cylindrical extension adapted to be closed by said inwardly projecting ring during the upward travel of said valve to term a dash-pot tor the purpose specified.

-l-. in a compressor for compressing air or other gas, a suction valve comprising a valve head and a cylindrical guide extension d1sposed within a piston; tins whereby said valve is maintained central with its seat, the spaces between said tins being adapted to term ga passages; a pin passed through the piston amt cylindrical valve guide; said pin being maintained in position by the cylinder walls; an extension on said cylinder; :1 piston trunk oi lesser diameter than the piston proper and integral therewith adapted to work in said cylinder extension as a guide, and adapted for connection to an operating rod; gas ports in said trunk, and means whereby said piston trunk is closed near its lower end.

in a (fOIYlPl'tSSOl' for compressing air or other gas. a suction valve coin n'ising a valve head. and a cylindrical guide extension disposed within a piston; [ins whereby said valve is maintained central with its seat; the spaces between said tins being adapted to term gas passages; a pin passed through the piston and cylindrical valve guide, said pin being maintained in position by the compressor cylinder all; an extension on said (ZOIX'IPI'CSSOL' cylinder; a piston trunk of lesser diameter than the piston proper and integral therewith, guided in said compressor cyliiuler extension and adapted For connection to an operating rod; gas ports in said trunk, and a relief valve disposed within said piston trunk and adapted to prevent any material accumulation of pressure, higher than suction pressure, in the crank casing.

(t. in a compressor for compressing air or other gas, a suction valve comprising a valve head and a cylindrical guide extension; a sleeve, provided with a valve seating, se cured to the piston, within which sleeve the said guide extension is disposed; means whereby said valve is maintained central with its seat; and a pin or pins passed llii'OlttIll the piston, sleeve, and valve guide; said pin or pins being maintained in position by the cylinder wall.

7. In a compressor for compressing air or other gas, a suction valve, comprising a valve head, and a cylindrical guide extension disposed within the piston; tins integral with said piston, adapted to maintain said valve central with its seat; and a plui'ality of pins adapted to pass through said piston wall and enter an annular recess in said guide.

S. In a compressor for compressing air or other gas, a suction valve comprising a valve head and a cylindrical extension disposed within the piston; fins on said extension adapted to bear against said piston, to maintain said valve central with its seat; projections on the lower part of said fins; slots provided in the piston, through which said projections are adapted to pass; and a pin passing through the piston and cylindrical extension on valve, such pin being maintained in position by the cylinder Wall.

In testimony whereof I have signed my name to this specification in the presence of 10 two subscribing witnesses.

BERNARD RATI-IMELL.

Witnesses JOHN I-IINDLEY WALKER, WALTER BERESFORD.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. C. 

